Discovering More Juvenile Myoclonic Epilepsy Genes by a Consortium

描述（由申请人提供）：美国约有30万青少年肌阵挛性癫痫（JME）患者，全球约有500万至1000万人患有此病，目前尚无治愈方法。因此，我们的总体目标是通过国际“GENESS”联盟加速发现JME的癫痫致病基因、其发病机制和治疗方法。该联盟包括发展中国家提供人类遗传资源的各种地点，例如许多大家庭，远远超过美国等西方社会所能完成的。到目前为止，大多数常见的遗传性癫痫被认为是由离子通道病变引起的。在这里，我们假设常见的癫痫，如JME，是由参与神经发生、细胞凋亡和神经母细胞迁移的发育基因突变引起的，例如具有EF手钙结合基序的基因，如Myoclonin1/EFHC1。为了在前期研究中验证发育性基因导致JME的假设，我们采用传统的连锁分析和全基因组扫描，对5个JME大家族（003、0J1、040、106和017）进行精细定位，确定了5个新的推定染色体位点，候选基因主要为发育性基因。LOD评分达到3.3的家族（0J1、106和016）是“最高优先级”，将在Aim 1中首先进行研究，因为我们使用LightScanner系统和测序来寻找在3或4代家族中分离出受影响的突变。我们将研究的候选发育基因包括家族106中的凋亡基因EGLN3，家族017中的干细胞增强基因CREG2，家族003中的4个EF-hand的Centrin1，家族040中的神经突生长诱导因子GPRIN2，以及28个CAE/JME家族先证中的Swiprosin （EFHD2, 2个EF-hand）。Aim 2 （Yrs2-3）将使用与染色体6p12-q14、14q11.2、2q11.2、18p11.23和10q11.2-21相连的相同STRPs/ snp标记复制连锁，以筛选其他14个大型“DNA准备”JME家族。然后，我们将使用构建的STS和tSNP单倍型筛选其他239个中等大小的具有JME的“DNA就绪”家族，并寻找更多的重组。Aim 3 （Yrs3-4）将使用CIDR （NIH国家人类基因组研究所）批准的Illumina Human Linkage set（6095个snp）对80个大中型“ready - dna”JME家族的681个样本进行基因组扫描，寻找更多引起癫痫的发育基因。目标4（1-5年）将从387个多代/多代和单一家族中收集DNA，并将其与已经收集的614个JME家族和1000个对照组结合起来。我们将申请CIDR （NIH国家人类基因组研究所）使用Illumina人类1 M Bead芯片（包括1 M snp和56K CNV探针）对所有1000个JME家族/单例和1000个对照进行基因组扫描，以联合分析5年级的连锁和连锁不平衡。只有明确(1)高风险的JME主要基因并建立其敲除/敲入小鼠模型，(2)导致其复杂遗传的JME风险等位基因，才能揭示其发病机制，并使治愈的希望成为现实。

DESCRIPTION (provided by applicant): For about 300,000 people in the USA with Juvenile Myoclonic Epilepsy (JME) and about 5 to 10 million persons, worldwide, with this disease, there is no cure. Thus, our general purpose is to accelerate discovery of epilepsy causing genes for JME, their pathogenetic mechanisms and cures through an international "GENESS" consortium. This consortium includes various sites in the developing world which provide human genetic resources, such as many large families, that far surpass what can be accomplished in Western societies like the USA. To the present time, most common genetic epilepsies are thought to be due to ion- channelopathies. Here we hypothesize that common epilepsies, such as JME, are caused by mutations in developmental genes that are involved in neurogenesis, apoptosis and neuroblast migration, such as genes with EF hand calcium binding motif like Myoclonin1/EFHC1. To test the hypothesis of developmental genes causing JME in preliminary studies, we used traditional linkage analysis and genome-wide scanning, then fine mapping in five large JME families (003, 0J1, 040, 106 and 017) and defined five new putative chromosome loci whose candidate genes are mainly developmental genes. Families (0J1, 106 and 016) which reached LOD score of 3.3 are "highest priority" and will be studied first in Aim 1 as we search for mutations that segregate with affecteds in 3 or 4 generations families using LightScanner system and sequencing. Examples of candidate developmental genes we will study are EGLN3, an apoptosis gene in Family 106, CREG2, an enhancer of stem cells, in Family 017, Centrin1 with 4 EF-hands in Family 003,GPRIN2, an inducer of neurite outgrowth, in Family 040 and Swiprosin (EFHD2 with 2 EF hands) in probands of 28 CAE/JME families. Aim 2 (Yrs2-3) will replicate linkage using the same STRPs/SNPs markers linked to chromosomes 6p12-q14, 14q11.2, 2q11.2, 18p11.23 and 10q11.2-21 to screen 14 other large 'DNA ready' JME families. We will then use constructed STS and tSNP haplotypes to screen 239 other medium-size 'DNA ready' families with JME and look for more recombinations. Aim 3 (Yrs3-4)will genome scan 681 samples of 80 large and medium-sized 'DNA-ready' JME families with Illumina Human Linkage set (6095 SNPs) already approved by CIDR (NIH National Human Genome Research Institute) and look for more epilepsy causing developmental genes. Aim 4 (Yrs 1-5) will collect DNA from 387 more multiplex/multigenerational and simplex families, and combine them with the already-collected 614 JME families and 1000 controls. We will apply to CIDR (NIH National Human Genome Research Institute) to genome scan all 1000 JME families/singletons and 1000 controls using the Illumina Human 1 M Bead chip (includes 1 M SNPs and 56K CNV probes) for joint analysis of linkage and linkage disequilibrium in Year 5. Only by defining (1) high-risk major JME genes and developing their knockout/knockin mice models, and (2) JME risk alleles that contribute to their complex genetics can pathogenetic mechanisms be unraveled and hopes for cures become a reality. PUBLIC HEALTH RELEVANCE: For about 300,000 people in the USA with Juvenile Myoclonic Epilepsy (JME) and about 5 to 10 million persons, worldwide, with this disease, there is no cure. To find a cure, we will define developmental Mendelian JME genes involved in neuronal genesis, migration and death, such as myoclonin with one EF hand calcium binding motif and the non-Mendelian risk alleles that contribute to complex genetics. Cures in JME can become a reality only by defining its many genes and then unravelling their epilepsy/disease causing mechanisms.